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Alloy 317L (UNS S31703) is a low carbon corrosion resistant austenitic chromium-nickel-molybdenum stainless steel. The high levels of these elements assure the alloy has superior chloride pitting and general corrosion resistance to the conventional 304/304L and 316/316L grades. The alloy provides improved resistance relative to 316L in strongly corrosive environments containing sulfurous media, chlorides, and other halides.

The low carbon content of Alloy 317L enables it to be welded without intergranular corrosion resulting from chromium carbide precipitation enabling it to be used in the as-welded condition. With the addition of nitrogen as a strengthening agent, the alloy can be dual certified as Alloy 317 (UNS S31700).

Alloy 317L is non-magnetic in the annealed condition. It cannot be hardened by heat treatment; however the material will harden due to cold working. Alloy 317L can be easily welded and processed by standard shop fabrication practices.

Chemical Properties:

C 0.035 Max

Si 0.075 Max

Mo 2.00 Max

P 0.04

S 0.03

Mo 3.00-4.00

Cr 18.00-20.00

Ni 11.00-15.00

Mechanical Properties:

Tensile Strength ksi (min.)              75

Yield Strength 0.2% Offset ksi (min.)      30

Elongation -% in 50 mm (min.)          40

Hardness (Brinell) MAX                217

Tensile Strength ksi (min.)              75

Yield Strength 0.2% Offset ksi (min.)      30

Elongation -% in 50 mm (min.)          40

Hardness (Brinell) MAX                21


Alloy 317L is commonly used to handle sulfur, pulp liquor, acid dyestuffs, acetylating and nitrating mixtures, bleaching solutions, severe coal and oil, and many chemical compounds. Some other applications that use alloy 317L include:

•      Paper and pulp handling equipment

•      Chemical and petrochemical processing equipment

•      Condensers in fossil and nuclear fueled power generation stations

•      Food processing equipment

•      Textile equipment